Crop Seedlings

The Hardening Off Process

Hardening off is a gradual process that helps seedlings grown indoors or in protected environments adjust to outdoor conditions, reducing the risk of transplant shock. To start the process, begin by moving seed trays outside in the morning sun. Gradually transition them to the afternoon sun as well. This allows them to get acclimated to the elements. However, if there’s frost on the horizon, bring them back inside to protect them. 

The hardening off process should be started about 1-2 weeks before you plan to transplant them for good. Keep a watchful eye on how they’re coping with being outside. If they start showing signs of stress, like wilting or yellowing leaves, dial back their outdoor time temporarily until they bounce back. Once your seedlings have successfully toughened up, it’s time to find them a permanent home, whether it’s in pots or in a garden bed. 

What To Do If There’s a Frost

If you find yourself facing an unexpected freeze after moving your crops outside, you can still protect your plants. Cover the plants with either a frost blanket, burlap, tarp, or bed sheets during the night it’s supposed to frost to shield them. If they do end up getting frosted over, gently mist the foliage to melt the frost, stopping any tissue damage and speeding up their recovery process. 

Plants to Start Hardening Off in Connecticut

Cool Weather Crops

Some cool weather crops that you can being the hardening off process with soon are: 

  • Cabbage 
  • Kale 
  • Broccoli 
  • Cauliflower 
  • Carrots 
  • Leeks 
  • Onions 
  • Parsnips 
  • Beets 
  • Kohlrabi 
  • Kale 
  • Lettuce 
  • Spinach 
  • Cilantro 
  • Swiss chard 
  • Parsley 

It’s important to remain vigilant, especially if there’s a risk of freezing temperatures below 25 degrees Fahrenheit. In such instances, cover these cold tolerating plants with a frost blanket, burlap, tarp, or bed sheets to protect them from potential damage.  

Warm Weather Crops 

Some warm weather crops that can be moved outside in a few months are: 

  • Tomatoes 
  • Eggplant 
  • Tomatillos 
  • Peppers 
  • Green Beans (as a second crop planting) 

Since these plants are less tolerant of the cold, it is critical to cover them if temperatures are going to drop below 32 degrees Fahrenheit. The general rule of thumb in Connecticut is to plant warm weather crops outdoors around Mother’s Day. 

All these crops thrive in full sun and most require consistent watering to maintain soil moisture levels. However, onions and eggplant are best suited to moderate watering practices, allowing the soil to dry slightly between waterings. 

Direct Sowing

Unlike many plants that require a period of hardening off before being planted outdoors, beans and peas can thrive when directly sown into their final growing spot. This method allows the seeds to establish themselves directly in the soil, bypassing the need for acclimation to outdoor conditions. As a result, beans and peas can produce robust harvests without the intermediate step of hardening off. For Connecticut’s 2024 planting season, the end of March is a great time for planting beans and peas, but they will only grow at the rate the weather allows.  

It is important to note that the actual growth and development of most plants will depend on factors such as temperature, sunlight, and moisture levels, which can vary and ultimately determine how quickly or slowly the plants will mature and produce a harvest. 

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